1. Field of the Invention
The present invention relates to a call setup, and more particularly, to a method of setup and controlling service connection.
2. Discussion of the Related Art
A mobile communication system provides services for voice and multimedia such as video. The service for voice communication includes transmitting and receiving voice information between users of mobile communication. Moreover, the service for multimedia communication includes transmitting and receiving, not only voice, but also still images and video.
According to recent trend, mobile stations are provided with diverse multimedia features such as taking still pictures and recording moving pictures. Generally, a transmission data rate of 8 kbps-13 kbps is needed to support voice communication, and a transmission data rate of 32 kbps-64 kbps is need to support multimedia communication.
When communicating using the mobile station (MS), it is necessary to transmit and receive service option information for identifying different types of services. For example, the service option information includes information on whether the provided service is for voice communication or multimedia communication. That is, the service option information includes information related to a type of voice codec for the voice communication service and a type of data used for multimedia service. Once the type of service is identified, each type of service is assigned a service option number, and using the service option number, each communication scheme can be identified. For example, when a multimedia service in form of video is transmitted, independently processed voice and video are first multiplexed. Here, a specific service option number can be assigned to the video transmission format for the multiplexed voice and video.
The multimedia service for video communication provides users with live images of other users to whom they in communicating. To realize such a communication service, a system that supports high data rate is needed. When video communication for display live images is implemented, the need for higher data rate and more broadband space become apparent and consequently takes up the system's capacity. As such, a base station (BS) is forced to support less number of mobile stations. From the user's perspective, the communication service charges associated with the multimedia service increases due to high cost of maintaining the service, and therefore, the users are likely to not use the video communication feature of the multimedia service as much as the less costly voice communication services.
To combat the high cost of using the video service, based on the user's selection, other cost saving services can be used. However, there is no service options related to providing alternative cost saving services, such as providing expressions or feelings of the user as opposed to providing live images which equates to high service charges. Even if such service options are provided, a MS with this service option cannot communicate with a MS without this service option. Further, transmission delay can be expected during the negotiation process in providing such a service option.